The primary structures of a number of iron-sulfur proteins and flavoproteins are under investigation. The purpose of these investigations is to ultimately learn the primary-tertiary structures of these proteins. Some of the investigations are being run jointly with X-ray crystallographers who are investigating the 3D structures of these proteins. A limited amout of research is being conducted on the solid phase synthesis of these proteins and on the immunological properties of these proteins. The ultimate goal is to prepare the groundwork for structure-function studies of these proteins, to obtain genetic and phylogenetic data about the organisms containing these proteins as well as to obtain information concerning the relationship between sequence and the conformation of proteins.